Next Issue
Volume 2, June
Previous Issue
Volume 1, December
 
 

Grasses, Volume 2, Issue 1 (March 2023) – 5 articles

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Reader to open them.
Order results
Result details
Select all
Export citation of selected articles as:
10 pages, 676 KiB  
Article
Influence of Slow- or Fast-Release Nitrogen in Xaraés Grass under Tropical Conditions
by Carlindo S. Rodrigues, Luís H. A. de Matos, Douglas dos S. Pina, Vagner M. Leite, Paula de A. Silva, Robério R. Silva, Taiala C. de J. Pereira, Henry D. R. Alba and Gleidson G. P. de Carvalho
Grasses 2023, 2(1), 47-56; https://doi.org/10.3390/grasses2010005 - 09 Mar 2023
Viewed by 1331
Abstract
Nitrogen (N) is a nutrient used worldwide in pasture fertilization. However, it is a very volatile element. Furthermore, inappropriate use promotes environmental pollution and economic losses. The present study was carried out to evaluate the effects of the N source on the productivity [...] Read more.
Nitrogen (N) is a nutrient used worldwide in pasture fertilization. However, it is a very volatile element. Furthermore, inappropriate use promotes environmental pollution and economic losses. The present study was carried out to evaluate the effects of the N source on the productivity and N utilization efficiency in Xaraés grass (Brachiaria brizantha cv. Xaraés) under tropical conditions. The randomized complete block design was used in a 3 × 2 × 4 factorial scheme: three seasons (rainy, dry, and transition), two N sources (fast-release = conventional urea, and slow-release = treated urea), and four N doses (0, 80, 160, and 240 kg N/ha/year). Forage accumulation per day differed (p < 0.0001) with the season and N dose. The interaction between those showed a positive linear effect (p < 0.0001) during the rainy season and transition. With increasing N doses, there was a linear increase in annual dry matter production and N accumulation. However, the N utilization efficiency (p < 0.0001) was reduced. Nitrogen sources did not affect forage accumulation and N utilization efficiency. Therefore, it is not recommended to replace fast-release nitrogen fertilization (conventional urea source) with a urease inhibitor (slow-release N source), promoting benefits with lower production costs. Full article
Show Figures

Figure 1

16 pages, 728 KiB  
Review
Alpine Grassland Degradation and Its Restoration in the Qinghai–Tibet Plateau
by Huakun Zhou, Xiaoyuan Yang, Chenyu Zhou, Xinqing Shao, Zhengchen Shi, Honglin Li, Hongye Su, Ruimin Qin, Tao Chang, Xue Hu, Fang Yuan, Shan Li, Zhonghua Zhang and Li Ma
Grasses 2023, 2(1), 31-46; https://doi.org/10.3390/grasses2010004 - 03 Mar 2023
Cited by 10 | Viewed by 3104
Abstract
The alpine grasslands of the Qinghai–Tibet Plateau are one of the most famous grazing ecosystems in the world, providing a variety of ecosystem functions and services. The rate of grassland degradation has been slowed by the implementation of national grassland restoration projects, but [...] Read more.
The alpine grasslands of the Qinghai–Tibet Plateau are one of the most famous grazing ecosystems in the world, providing a variety of ecosystem functions and services. The rate of grassland degradation has been slowed by the implementation of national grassland restoration projects, but the degradation of grasslands on the Qinghai–Tibet Plateau has not yet been fundamentally reversed, and some grasslands are still degraded to varying degrees. The main causes of grassland degradation on the Qinghai–Tibet Plateau are both human and natural factors. Human factors include overgrazing, over-cultivation, indiscriminate digging and mining, mineral resource development, infrastructure construction and use, and tourism development. Natural factors include climate change, wildlife destruction, pests, etc. Based on the principles of restoration ecology, a number of effective practices and integrated management responses for restoring degraded grasslands have been developed on the Qinghai–Tibet Plateau. The degraded grassland restoration practices include fencing, fertilization, sown grassland establishment, rodent control, and grazing management. Based on these practices, the comprehensive restoration of degraded grasslands and the establishment and sustainable management of sown grasslands in the alpine grasslands of the Qinghai–Tibet Plateau should be further strengthened, and research on the mechanisms of grassland degradation and restoration should be further developed. Full article
Show Figures

Figure 1

8 pages, 5069 KiB  
Communication
Relationship between NDVI of Patches and Cover Area of Grasses, Shrubs and Bare Soil Components of a Semi-Arid Steppe from North-West Patagonia, Argentina
by Clara Fariña, Valeria Aramayo, Daiana Perri, Valeria Martín Albarracín, Fernando Umaña, Octavio Augusto Bruzzone and Marcos H. Easdale
Grasses 2023, 2(1), 23-30; https://doi.org/10.3390/grasses2010003 - 06 Feb 2023
Cited by 1 | Viewed by 1612
Abstract
Distinguishing the contributions of different vegetation cover such as shrubs and grasses components into the primary production in arid and semi-arid rangelands is a key step to understanding changes at a landscape scale. The aim was to assess the contribution of shrubs, grasses [...] Read more.
Distinguishing the contributions of different vegetation cover such as shrubs and grasses components into the primary production in arid and semi-arid rangelands is a key step to understanding changes at a landscape scale. The aim was to assess the contribution of shrubs, grasses and bare soil components into a total biophysical variable at a patch level, and the relationship between that biophysical variable and remote sensing vegetation index, in a grass–shrub steppe from North-West Patagonia, Argentina. We conducted a field survey in the period 2015–2017 to analyzing the relationship between monthly values of Normalized Difference Vegetation Index (NDVI) of two grasses, two shrub species and bare soil, weighted by their cover area at a patch level, and the concomitant patch NDVI records, respectively. The contribution of the patch components to the total NDVI value at a patch level was additive. The relationship between the weighted NDVI of patch components and the concomitant NDVI value at a patch level along time was linear for perennial grasses and deciduous shrub–grass patches, but linearity was not significant for most perennial shrub–grass patches. Differences among patch compositions and their surface reflectance suggest the need to move forward in a more precise distinction of the floristic composition of patches, to better understanding their contribution to NDVI temporal dynamics at a landscape scale. Full article
Show Figures

Figure 1

11 pages, 845 KiB  
Article
Population Dynamics of Digitaria sanguinalis and Effects on Soybean Crop under Different Glyphosate Application Timings
by Fernando H. Oreja, Mateo Stempels and Elba B. de la Fuente
Grasses 2023, 2(1), 12-22; https://doi.org/10.3390/grasses2010002 - 03 Feb 2023
Viewed by 1703
Abstract
Large crabgrass (Digitaria sanguinalis) is one of the most problematic weeds in summer crops in Argentina. Emergence throughout the season of several cohorts allows the weed to escape postemergence control. Demographic models are useful tools to understand and compare the effect [...] Read more.
Large crabgrass (Digitaria sanguinalis) is one of the most problematic weeds in summer crops in Argentina. Emergence throughout the season of several cohorts allows the weed to escape postemergence control. Demographic models are useful tools to understand and compare the effect of different agronomic management decisions on weed population growth, as well as to identify critical functional stages that affect population growth rates. The objectives of this work were (i) to study population dynamics of D. sanguinalis in soybean, (ii) to determine the effect of glyphosate application timing on weed demographic parameters and soybean yield losses, and (iii) to evaluate the effect of weed density on soybean yield loss. A field experiment was conducted in two locations, in a completely randomized design with three replicates. Treatments included a control without glyphosate and glyphosate applied at soybean stages V4 or R1. The demographic stages (initial seedbank, seedlings, and adult plants) and parameters (establishment, survival, and fecundity) were estimated. Reproductive organs were evaluated in each cohort, including raceme per plant, spikelets per raceme, and seeds per spikelet. Weed and crop biomass and yield crop were assessed at harvest. Three cohorts were identified, the first of which emerged in November and contributed 93% of the total seedlings and 71% of the total adults. Glyphosate applied at V4 reduced the survival rate of the first cohort, as well as the total shoot biomass and the fecundity rate, increasing the biomass and crop grain yield. Both application timings affected tillers per plant, racemes per tiller, and fertile spikelets per raceme. Glyphosate at R1 did not effectively reduce weed competition, but reduced seed production as application at V4. Yield losses estimated with the model of the rectangular hyperbola according to weed density showed a yield loss at low densities (I) of 18%, and a maximum yield loss (A) of 82%. To avoid yield losses, herbicide applications targeting the first cohort are more effective than later applications targeting subsequent cohorts. However, at both times glyphosate applications reduced the number of seeds entering the seedbank, and therefore the population growth rate. Full article
Show Figures

Figure 1

11 pages, 672 KiB  
Brief Report
Morphological and Productive Characteristics and Chemical Composition of Grasses in Degraded Areas Subjected to Pasture Recovery Methods
by Raquel Souza, Ricardo Edvan, Larissa Fontes, Tairon Dias e Silva, Alex da Silva, Marcos Araújo, Rafael Miranda, Ronaldo Oliveira, Elzania Pereira, Evyla Andrade, José Pereira Filho and Leilson Bezerra
Grasses 2023, 2(1), 1-11; https://doi.org/10.3390/grasses2010001 - 05 Jan 2023
Cited by 1 | Viewed by 1717
Abstract
The objective of this study was to evaluate the morphological characteristics, yield and chemical composition of grasses in degraded areas subjected to pasture recovery methods. The randomized block design in a factorial scheme (4 × 5) with four replications (blocks) was used. The [...] Read more.
The objective of this study was to evaluate the morphological characteristics, yield and chemical composition of grasses in degraded areas subjected to pasture recovery methods. The randomized block design in a factorial scheme (4 × 5) with four replications (blocks) was used. The first factor was composed of four methods of pasture recovery: Closed pasture (CLP); Weed control (WC); Soil fertilization (SF); and Weed control + Soil fertilization (WC + SF). The second factor was composed of five species used for pasture recovery: Brachiaria brizantha cv. Marandu, Brachiaria brizantha cv. MG5, Brachiaria brizantha cv. MG4, Andropogon gayanus cv. Planaltina and Panicum maximum cv. Mombaça. The structural characteristics of green biomass yield, dry biomass yield and chemical composition were assessed in those grasses. An effect of the interaction (p < 0.05) between forage species and recovery methods on number of clumps, plant height and clump diameter, with superiority for cultivar MG4 in the WC + SF method. The green biomass yield was low in the evaluated grasses because of the advanced stage of the degradation of the pastures. Dry biomass yields increased (p < 0.05) when the WC + SF method was adopted, with a good response of grass MG4. There was an interaction (p < 0.05) between species and recovery methods on dry matter, mineral matter and neutral detergent fiber contents of the grasses, especially Marandu grass. The different types of grasses responded positively to the methods of pasture recovery with increased biomass and nutritional quality. Full article
Show Figures

Figure 1

Previous Issue
Next Issue
Back to TopTop